Rotatable electric connector

ABSTRACT

An arrangement in which a cylindrical shell-shaped member has a plurality of electrically conductive rings attached to the interior wall of the shell-shaped member which is made of electrically insulating material. Electrical conductors joined to the conductive rings extend from one end of the cylindrical shell-shaped member for connecting to a source of power. A cylindrical core-shaped member is rotatable within the shellshaped member and has mounted on it a plurality of conductive rings for contacting respectively the rings attached to the shell-shaped member. Electrical conductors extending from the interior of the core-shaped member are connected to the conductive rings on the core member and are rotatable with respect to the conductors extending from the shell member while transmitting power from the source.

United States Patent [191 Campo Feb. 18, 1975 ROTATABLE ELECTRIC CONNECTOR [76] Inventor: Louis Campo, 99 Waverly Ave.,

Patchogue, NY. 11772 [22] Filed: June 26, 1973 [21] Appl. No.: 373,857

[52] U.S. Cl 339/8 R [51] Int. Cl H0lr 39/00 [58] Field of Search 339/5, 8, 58, 183

[56] References Cited UNITED STATES PATENTS 1,649,276 11/1927 Adam 339/8 PB 1,743,118 1/1930 Couture et al. 339/8 P 2,712,116 6/1955 Baumann 339/8 P 3,185,951

5/1965 LeBeau 339/5 M Primary Examiner-Richard E, Moore Attorney, Agent, or FirmJoseph F. Padlon [57] ABSTRACT An arrangement in which a cylindrical shell-shaped member has a plurality of electrically conductive rings attached to the interior wall of the shell-shaped member which is made of electrically insulating material. Electrical conductors joined to the conductive rings extend from one end of the cylindrical shell-shaped member for connecting to a source of power. A cylindrical core-shaped member is rotatable within the shell-shaped member and has mounted on it a plurality of conductive rings for contacting respectively the rings attached to the shell-shaped member. Electrical conductors extending from the interior of the coreshaped member are connected to the conductive rings on the core member and are rotatable with respect to the conductors extending from the shell member while transmitting power from the source.

6 Claims, 10 Drawing Figures 1 ROTATABLE ELECTRIC CONNECTOR BACKGROUND OF THE INVENTION In the use of electrical appliances such as electrically heated irons, hair dryers, for example, the electrical cord connecting the appliance to a utility outlet becomes often twisted and coiled as a result of the manual motions applied by the user to the electrical appliance. Such twisting and coiling of the electrical cord causes these cords to shorten in length and give rise to irritation to the user who is required to continuously straighten the cord in order to avoid entanglement of the cord. The entanglement and twisting of the cord, furthermore, may interfere with the users proper operation of the appliance, and may even cause accidents while the user is attempting, for example, to straighten the cord while using an electrically heated iron. While rotary electrical connectors have been known in the art, these have been highly complex in design and construction to the extent that it has not been feasible to use such conventional connectors for consumer applications. The conventional rotary electrical connectors, moreover, are highly unreliable in operation since they will brake contact at intermittent instance of time producing sparking at the moveable electrical contacts and inoperativeness of the appliance.

Accordingly, it is an object of the present invention to provide a rotatable electrical connector which is simple in design and construction.

Another object of the present invention is to provide a rotatable electrical connector which may be easily and economically fabricated and assembled.

A further object of the present invention is to provide a rotatable electrical connector of the foregoing character which may be readily disassembled without the application of special tools, for purposes of maintenance and repair.

Yet another object of the present invention is to provide a rotatable electrical connector as described, which may be produced at substantially low cost for consumer applications, and which will transmit a substantially large amount of power required by substantially larger electrical appliances.

SUMMARY OF THE INVENTION The objects of the invention are achieved by providing a connector arrangement in which a cylindrical shell-shaped member has two copper rings attached or fixed to the interior wall of the shell member. The two copper rings are spaced from each other and the shell member is made of electrically insulating material, so that the copper rings are electrically isolated from each other. Two electrical conductors or leads are respectively attached to the two copper rings by soldering, and these two conductors pass through a central opening of a cap attached to one end of the shell member. The other ends of these two electrical conductors may be connected to an electrical plug which may be inserted into an electrical utility outlet, for example.

The two copper rings attached to the interior wall of the shell member engage in electrical contact, two respective copper rings mounted on a core-shaped member which is rotatable within the shell member. The two copper rings on the core member are fixed to the external surface of the core member and are rotatable with respect to the copper rings attached to the shell mem ber, while maintaining electrical contact between the respective rings. Two electrical conductors are attached by soldering, for example, to the interior of the copper rings on the core member, and extend through a central opening of a cap attached to one end of the core member. These two electrical conductors attached to the copper rings mounted on the core member may be connected to the electrical appliance to which power is to be fed. The copper rings on the core member as well as within the shell member have unobstructed contact surfaces, whereby electrical contact between the copper rings is continuously maintained while the core member rotates with respect to the shell member. When the electrical conductors connected to the copper rings on the core member are connected to an appliance which rotates during useage, the core member rotates with respect to the cylindrical member and the conductors connected to the source of power can remain stationary in space and not be subjected to twisting, for example.

The novel features which are considered as characteristic are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view through the central axis of the shell-shaped member, and shows the mounting of the copper rings together with the connecting leads within the shell-shaped member, in accordance with the present invention;

FIG. 2 is a sectional view through the central axis of the core-shaped member which is rotatable within the shell-shaped member of FIG. 1.;

FIG. 3 is a sectional view of a cap member for attaching to one end of the core member of FIG. 2;

FIG. 4 is an end view of the cap member of FIG. 3.;

FIG. 5 is a sectional view of a cap member attached to one end of the shell member of FIG. 1;

FIG. 6 is an end view taken along line 6-6 in FIG.

FIG. 7 is a side view of a cover attached to the shell member of FIG. 1;

FIG. 8 is an end view of the cover of FIG. 7;

FIG. 9 is a sectional side view of a cap member attached to the other end of the shell member of FIG. 1; and

FIG. 10 is an end view of the cap member of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, and in particular to FIG. 1, a shell-shaped member 10 has a cylindrical plastic body 12. This body 12 carries within its interior, two copper rings 14 and 16. The copper rings are fixed or attached to the internal wall of the body 12. A simple way to attach or mount the rings 14 and 16 is by a force fit, for example. The two copper rings 14 and 16 are spaced from each other so that they are electrically isolated from each other. Electrical conductors 18 and 20 are connected, respectively, to copper rings 16 and 14. The joining of the electrical conductors to the copper rings may be achieved by the conventional method of soldering, for example. Grooves or slots 22 and 24 are cut in the cylindrical body 12 for admitting the electrical conductors 18 and 20. With the presence of the grooves 22 to the ring 16 and lies within the groove 22 shorter in length than the groove 24.

A core-shaped member 26, shown in FIG. 2, has a plastic body 28 on which are mounted copper rings 30 and 32. These copper rings 30 and 32 are fixed or attached to the body 28 by a force fit, for example. The core member 26 is rotatable within the shell member in FIG. 1, and the copper rings 30 and 32 engage, respectively, the copper rings 14 and 16, when the core member 26 is inserted into the shell member 10 and rotates therein. The dimensions of the copper rings are such that the ring 14 is in electrical contact at all times with the ring 30, while the ring 16 is in contact with the mating ring 32, when the core member 26 is assembled within the shell member 10.

Electrical conductors 34 and 36 are connected, respectively to the copper rings 30 and 32, on the core member 26. The joining of these conductors 34 and 36 to the respective ring, is achieved by soldering on the internal surfaces of the rings. The plastic body 28 has grooves 38 and 40, furthermore, into which the conductors 36 and 34, respectively, may be laid for joining to the internal surfaces of the respective copper rings. By inserting the conductors 34 and 36 in the grooves 38 and 40, in this manner, the external surface of the core member 26 may rotate freely within the interior of the shell member 10 without interference from the conductors 36 and 34. When assembled within the shell member 10, the conductors 34 and 36 extend from the end of the shell member 10, which is opposite to the end from which the conductors l8 and extend.

A cap member 42, shown in FIG. 3, is attached to the end of the core member 26 from which the conductors 36 and 34 extend. The cap member 42 may be attached to the body 28 of the core member, by screws inserted through holes 44 and passing into threaded openings 46 in the body 28. When the cap 42 is attached to the body 28, in this manner, the ends of the conductors 34 and 36 lie within the space 48 in the cap 42. The ends of these conductors 34 and 36 may be connected to terminal screws, for example, passing through holes 50 in the cap 42. The cables feeding the appliance, for example, may then be also secured to the terminal screws passing through the holes 50, and thereby transmit the power fed by the conductors 34 and 36. With the cap 42 attached in place to the body 28 of the core member 26, the ends of the leads or conductors 34 and 36 are firmly held in place through the terminal screws passing through the holes 50.

After the core member 26 is rotatably inserted into the shell member 10, with the cap 42 attached to the body 28, a further cap member 52 is attached to the cylindrical body 12 of the shell member 10. The attachment of the cap 52 to the body 12 is achieved by the passage of screws through holes 54 in the cap 52, and threadably inserted into threaded openings 56 in the body 12. The cap 52 has an interior space 58 for accommodating the terminal screws connected to the conductors 34 and 36. Cables leading to the appliance from the terminal screws within the space 58 pass through the opening 60 of the cap 52. With the cap 52 in place, the terminal screws within the space 58 are not exposed, so that the user is protected from coming accidentally into contact with these terminal screws.

The leads or conductors l8 and 20 connected to the copper rings mounted within the shell member 10 have their ends connected to terminal screws passing through openings 62 of a cover 64 attached to the ends of the shell body 12 from which the conductors l8 and 20 extend. The cover 64 is attached to the shell body 12 through screws passing through the cutouts 66 in the cover 64, and threadably inserted into threaded holes 68 in the body 12. Thus, the terminal screws passing through the opening 62 of the cover 64 serve to fasten securely in place the ends of the conductors l8 and 20. Connected to the same terminal screws passing'through the openings 62, may be a cable leading to the source of power, as for example, an electrical utility outlet. The cover 64 is, furthermore, provided with a curved portion 70 projecting into the interior of the body 12 when the cover is attached in place. This curved portion 70 is in contact with a similar curved portion 72 on the core member 26 when the latter is rotatably in serted within the body 12. The curved portions 70 and 72 serve to constrain the core member 26 in axial motion along the central axis of the shell member 10. Thus, the curved portions 70 and 72 serve as thrust elements which sustain the thrust reaction between the core member 26 and the shell member 10.

After the ends of the conductors 18 and 20 are secured or fastened in place through terminal screws passing through the holes 62 of the cover 64, a cap member 74 is attached to the body 12 by the passage of screws through the openings 76. These screws passing through the opening 76 are the same screws passing through the cutouts 66. Accordingly, the cover 64 is held firmly in place by screws passing through openings 76 and 66 when the cap 74 is assembled in place. The cap member 74 has a space 78 for accommodating the terminal screws passing through the opening 66 for holding in place the ends of the conductors 18 and 20. A cable leading to the electrical supply of power may pass through the opening 80 of the cap 74 and be connected to the terminal screws to which the conductors 18 and 20 are attached. The cap member 74 may be made substantially similar to the cap member 52, shown in FIG. 5. Thus, the two cap members in FIGS. 5 and 9 used to cover the ends of the shell member 10 may be made substantially identical. At the same time, the cavities 74 and 58, as well as openings 60 and 80, may have somewhat different dimensions for accommodating the respective terminal screws and connecting cables. The caps 52 and 74 as well as the cover 64 may be made of plastic or electrically insulating material. When the core member 26 is inserted within the shell member 10, and the covers and caps are attached in place, electrical power may be conducted from the leads 18 and 20 to the leads or conductors 34 and 36 of the rotatable connector.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of electrical conductors differing from the types described above.

While the invention has been illustrated and described as embodied in electrical conductors, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

1 claim:

1. A rotatable electrical connector comprising, in combination, a shell-shaped member of electrically insulating material; a plurality of electrically conductive rings attached to the internal wall of said shell-shaped member in spaced relationship from each other; a coreshaped member of electrically insulating material and rotatable within said shell member, said core-shaped member being supportedby said shell-shaped member on the interior of said shell-shaped member; a plurality of conductive rings mounted in spaced relationship on the external surface of said core-shaped member, each ring on said core-shaped member being in electrical contact with one ring attached to said shell-shaped member; a first plurality of conductors connected to said conductive rings on said shell-shaped member; and a second plurality of conductors connected to said conductive rings on said core-shaped member, so that electrical current applied to said first plurality of conductors is transmitted to said second plurality of conductors through said conductive rings while said coreshaped member is rotating with respect to said shellshaped member and when said core-shaped member is stationary with respect to said shell-shaped member, said shell-shaped member and said core-shaped member being of cylindrical shape, said conductive rings on said shell-shaped member and said core-shaped member being spaced along the axes of said cylindrical shell-shaped member and core-shaped member; a cover member attached to one end of said shell-shaped member, said first plurality of conductors being attached to said cover member; a first cap member attached to one end of said core-shaped member, said second plurality of conductors being attached to said cap member; a second cap member abutting said first cap member and fastened to said shell-shaped member for covering the ends of said second plurality of conductors; and a third cap member attached to said shellshaped member for covering the ends of said first plurality of conductors, said third cap member abutting said cover member.

2. The connector as defined in claim 1 including grooves in said shell-shaped member for insertion of said first plurality of conductors along the axial length of said shell-shaped member, and including grooves in said core-shaped member for the insertion of said second plurality of conductors along the axial length of said core-shaped member, said grooves holding said conductors so that said core-shaped member is rotatable freely within said shell-shaped member.

3. The connector as defined in claim 2 wherein said first plurality of conductors are connected to the respective conductive rings on the exterior surfaces of said conductive rings, whereby the internal wall surfaces of said conductive rings within said shell-shaped member are free of said first plurality of conductors, said second plurality of conductors being connected to the respective conductive rings on said core-shaped member on the internal walls of said conductive rings on said core-shaped member, whereby the external surfaces of the conductive rings on said core-shaped member are free of said second plurality of conductors.

4. The connector as defined in claim 1 wherein said electrically insulating material is plastic.

5. The connector as defined in claim 3 wherein said cover member has a curved portion and said coreshaped member has a mating curved portion for mating with said curved portion of said cover member, whereby axial thrust between said coreshaped member and said shell-shaped member is sustained by said curved portions on said cover member and said coreshaped member.

6; The connector as defined in claim 1 wherein said second cap member and said third cap member have interior spaces for retaining terminal screws connected to the ends of said first plurality of conductors and said second plurality of conductors. 

1. A rotatable electrical connector comprising, in combination, a shell-shaped member of electrically insulating material; a plurality of electrically conductive rings attached to the internal wall of said shell-shaped member in spaced relationship from each other; a core-shaped member of electrically insulating material and rotatable within said shell member, said core-shaped member being supported by said shell-shaped member on the interior of said shell-shaped member; a plurality of conductive rings mounted in spaced relationship on the external surface of said core-shaped member, each ring on said core-shaped member being in electrical contact with one ring attached to said shellshaped member; a first plurality of conductors connected to said conductive rings on said shell-shaped member; and a second plurality of conductors connected to said conductive rings on said corE-shaped member, so that electrical current applied to said first plurality of conductors is transmitted to said second plurality of conductors through said conductive rings while said core-shaped member is rotating with respect to said shell-shaped member and when said core-shaped member is stationary with respect to said shell-shaped member, said shell-shaped member and said core-shaped member being of cylindrical shape, said conductive rings on said shell-shaped member and said core-shaped member being spaced along the axes of said cylindrical shellshaped member and core-shaped member; a cover member attached to one end of said shell-shaped member, said first plurality of conductors being attached to said cover member; a first cap member attached to one end of said core-shaped member, said second plurality of conductors being attached to said cap member; a second cap member abutting said first cap member and fastened to said shell-shaped member for covering the ends of said second plurality of conductors; and a third cap member attached to said shell-shaped member for covering the ends of said first plurality of conductors, said third cap member abutting said cover member.
 2. The connector as defined in claim 1 including grooves in said shell-shaped member for insertion of said first plurality of conductors along the axial length of said shell-shaped member, and including grooves in said core-shaped member for the insertion of said second plurality of conductors along the axial length of said core-shaped member, said grooves holding said conductors so that said core-shaped member is rotatable freely within said shell-shaped member.
 3. The connector as defined in claim 2 wherein said first plurality of conductors are connected to the respective conductive rings on the exterior surfaces of said conductive rings, whereby the internal wall surfaces of said conductive rings within said shell-shaped member are free of said first plurality of conductors, said second plurality of conductors being connected to the respective conductive rings on said core-shaped member on the internal walls of said conductive rings on said core-shaped member, whereby the external surfaces of the conductive rings on said core-shaped member are free of said second plurality of conductors.
 4. The connector as defined in claim 1 wherein said electrically insulating material is plastic.
 5. The connector as defined in claim 3 wherein said cover member has a curved portion and said core-shaped member has a mating curved portion for mating with said curved portion of said cover member, whereby axial thrust between said core-shaped member and said shell-shaped member is sustained by said curved portions on said cover member and said core-shaped member.
 6. The connector as defined in claim 1 wherein said second cap member and said third cap member have interior spaces for retaining terminal screws connected to the ends of said first plurality of conductors and said second plurality of conductors. 